I'm a big fan of neck knives & have worn one daily for several years. FWIW, my specs for an ideal
concealed carry NK w/sheath are: <= 7" OAL; <= 4 oz, the lighter the better; and, not much more than 1/4" thick, including scales. Note the emphasis here is on concealed carry. I can wear a NK with these specs under even a light t-shirt and have it be virtually undetectable.
Despite having many fancier ones, the one I keep coming back to for everyday carry is a plain skeleton handle Perrin La Griffe Fang. At 5" OAL, < 3 oz, and ~ 1/4" thick at the sheath, it truly disappears. When I'm going to be in a situation where I may be limited in what other pieces I can carry, I'll switch to my large La Griffe. It gives me a 3 1/2" cutting edge & still fits within my specs for concealed carry.
IMO, I think you would be hard pressed to find a better defensive knife than a La Griffe in this size category. They work well in both forward & reverse grips and, although the hole can slow transitions a bit, it makes it very difficult to disarm.
For utility purposes where concealment is not an issue, such as when camping or canoeing, I'll usually opt for a different blade shape with larger handle. Light weight is still important for comfortable all-day carry but size is not as limiting a factor. Two of my favorites in these situations are Dozier's Canoe model & RJ Martin's Handiman.
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Cheers,
Brian
(formerly bcaffrey)
He who finishes with the most toys wins.